Mark Tinkler's young charges held their nerve from the penalty spot to beat Forest Green Rovers at the Riverside on Wednesday.
Progress in the FA Youth Cup was hard to come by for our U18s, but a penalty shoot-out proved decisive after the game ended 1-1.
The visitors had taken the lead shortly before half-time, courtesy of Vaughan Covil, despite Boro enjoying the better of proceedings.
But the equaliser came shortly after the hour when Terry Stephenson capitalised after the visitors failed to clear the lines.
Hayden Hackney came within a whisker of winning the tie in normal time, but his effort was just wide.
The extra time crowd was bolstered by a noisy Red Faction contingent, fresh from their xmas celebrations, but despite a late flurry, Boro were unable to find a second goal in extra time.
The tie went to penalties and Harry Flatters was the hero of the hour, making a vital save, and Alberto Balde ensured progress when he made it five out of five for Boro.
An away tie with either Scunthorpe or West Bromwich now awaits in the fourth round.